#include <iostream>

using namespace std;

const int N = 21, M = 410;

int n, m;
int a[M];

int main()
{
	cin >> n >> m;
	for(int i = 1; i <= m; i++)
	{
		int x, y; cin >> x >> y; x--; y--;
		a[i] |= (1 << x);
		a[i] |= (1 << y);
	}
	
	int ret = 0;
	for(int st = 0; st < (1 << n); st++)
	{
		bool flag = true;
		for(int i = 1; i <= m; i++)
		{
			if((st | a[i]) == st)
			{
				flag = false;
				break;
			}
		}
		ret += flag;
	}
	
	cout << ret << endl;
	
	return 0;
} 














